Summary

Mitral valve endocarditis complicating hypertrophic cardiomyopathy is rare especially in the absence of significant mitral regurgitation. The occurrence of large vegetation and an abscess formation is even rarer. Endocarditis occurs predominantly on the left ventricular aspect of the anterior mitral leaflet. We report a case of a 34-year-old woman with asymptomatic obstructive hypertrophic cardiomyopathy who developed mitral valve endocarditis with large vegetation and subsequently an abscess caused by a rare organism Gemella morbillorum, following dental extraction. The patient underwent antibacterial therapy followed by successful mitral valve replacement for severe mitral regurgitation and her postoperative course has been asymptomatic so far. This case is unique in describing endocarditis by a rare organism as a cause of large vegetation and an abscess on an unusual site on the mitral valve leaflet without predisposition of haemodynamically significant mitral regurgitation and illustrates the potential lifesaving role of timely intervention.